Air supply for internal-combustion engines



Jufly 1 1924.

' 1,499,599 E. SEPPELER ET AL AIR SUPPLY FOR INTERNAL COMBUSTION ENGINES Filed Aug. 29 1921 2 Sheets-Sheet l MW 1 1924. I 1.499,

E. SEPPELER ET AL AIR SUPPLY FOR INTERNAL COMBUSTION ENGINES Filed Aug. 29 1921 2 Sheets-Sheet 2 Patented duly ll, lhfld.

- 1 l at EDWARD @WFMFR, OF FllfihLIN-NEUKOLLN, AND PAUL SCHWTTLER, F BERLIN HALJENSEE, GERMANY.

Application filed flagrant 29, 1921. Qerlal Ito. 119mm.

(GRANTED UNDER THE IIPRO'VIEEONB OF THE .Ml'l OF MARCH 3, 1921, all @Tll'l. I, 191%.)

To all whom it may concern:

Be it known that we, EDUAim Snrrnnnn and PAUL SoHii'rTLnR, both citizens of Germany, residing at Berlin-Neukolln, Gera many, and Berlin-Halensee, Germany, re-

spectively, have invented certain new and useful Improvements in Air Supply-for Internal-Combustion Engines (for which We have filed applications in Germany, Octo- 19 her 13, 1919, patent granted No. 354622, and

November 28, 1919, Serial No. 38 838-; England, January 10, 1921, Patents hlos. 157918 and 157919; France, March 30, 1921, Patent No. 533047 Italy, April 9, 1921, Serial No.

301/1397), of which the following is a speci-' the same 1n all cases.

fication.

Our invention relates to devices for regulating the supply of combustion air to internal combustion engines.

lin internal combustion engines, in which the fuel is supplied by a fuel pump, the output is regulated by altering the delivery of the pump, for instance, by increasing or r ducing the pump stroke. Together w1th 99 the regulation of the fuel pump, the air supply must be regulated in such a manner, that per stroke or in the unit of time a greater or lesser weight of air is supplied to the engine. It is old for this purpose to to connect the device, by which the stroke of the pump is regulated, with a throttlmg disc or valve by which the supply of an is regulated, so that to every position of the fuel regulating device there corresponds a defitt nite and invariable position of the am throttling device. The ratio of fuel and air is then the same for all leads or for all presi sure ratios. 7

Such a-device can however only be used ll so long as the number of revolutions of the motor remains substantially constant. If the number of revolutions varies considerably, it is not possible to maintain a constant ratio between fuel and air b means of such a device. llf the number 0 revolutions is increased, the fuel supply will be increased in proportion, if the adjustment of the pump is unaltered, but the supply of air would not be increased in proportion, to for the reduction of pressure at the throttle increases with increasing air velocity, and the weight of air drawn into the engine will be reduced accordingly.

an air float b, which may also be desi l[t is an object of our invention to provlde a regulating evice which will always supply a correct mixture when the load or the number of revolutions is altered, so that the engine has the necessary flexibility for all conditions of operation. This is achieved by providing, besides the device for ad ustmg the area of the air pipe, which device is connected wth the fuel control, a further throttle which automaticall adusts itself according to the number 0 revolutlons of the engine, that is the existing air veloclty at the throttle, so that the reduction of pressure or the'weight of air drawn into the engine at each stroke is approximately A device capable of such self-adjustment is the so called air float, that is a member of suitable form which consists of a body floating under the action of a stream of air. According-to-our invention we arrange an air float at the rear of a throttling opening which, in a manner per se known, is adjustable as to its area in dependency upon the regulation of the fuel pump.

In the drawings aflixed to this specificatron and forming part thereof several devices embodying our invention are illus trated diagrammatically by Way of example. In the drawings Figs. 1 to 3 show vertical sections, several mtzidifications of the air float arrangement, an

Fig. 4 is a similar view of another device adapted for two cycle engines.

Referring now to Figs. 1 to 3, a throttlin device a is arranged at a suitable point 0 the air supply pipe, which, in a known manner, is adjusted in conjunction with the regulation of the fuel pump, for instance together with the stroke of said pump.

In the modification illustrated in Fig. 1, the throttle has the form of a so-called iris diaphragm, while in Figs. 2 and 3 it is a slide. Above the throttle there is arrangeg e in various ways. In Figs. 1 and 2 it i s so designed that it is loaded only by its own weight, whereas in Fig. 3 it is closed principally by a spring 0. In the construction illustrated in Figs. 1 and 2 the load of the float and therefore the diflerence of pressure produced atthe throttle is constant,

till

lit

whereas in the modification shown in Fig. 3 the load can be varied.

If, for example, a-100 H. P. engine 1s loaded with one fifth of its normal load at low velocity, it will be necessary to close the throttlea considerably. The air supply to the engine is now heavily throttled, because the weight of the air float is distrlbuted over a small area. If the number of revolutions increases, the composition of the mixture is not influenced, for the same uantity of fuel is supplied to the engine by t e ump at every stroke as at low velocity, ut the total consum tion of fuel 1n the unit of time is increase. in proportion to the increase of velocity. The air supply 1ncreases in roportion, which is automatically eflecte by the air float b rising. With the air float, it is therefore possible, to supply to the motor the correct weight of air per stroke, according to the alteration of its number of revolutions, without adjusting the throttle a, if it be adjusted to a given position. As the areas are variable, while the load on the area is constant, the air velocity at the inlet opening will be constant.

If desired, it is also possible with this device, to somewhat increase or reduce the weight of air per volume of stroke, which 1s effected by a suitable arrangement of the guiding means and loading on the float.

The arrangement shown in Fig. 3 is more suitable for this pur ose. Here the flap b which forms the air oat, is light and loaded with a spring. The position of that spring and with it the direction and lever arm of the spring power can be adjusted by means of handle at and segment e. In a given position of lever d the load will be constant for the entire stroke of the flap, whereas, if the lever (Z be displaced to either side of this position, the load will be increased or reduced with the stroke. By alterin the load of the spring, the amount of loading of the area. can be varied in which case the slide a may be dispensed with.

Fig. 4 shows the application of our invention to two cycle engines. In these, the air is supplied to the working cylinder f by means of a charging pump g. According to the particular embodiment of our invention, in such two cycle en 'nes the suction or discharge valve of the ci arging pump is replaced by the air control. The opening through. which the air passes, is periodically opened and closed in this case. If the air control were simply inserted, for in stance, in advance of the suction valve of the charging pump, this would involve the drawback that the conditions, which have been correctly adjusted by the control, will be modified again by the valve. It is ma terial that there should be no controlled air passage behind the air regulating device.

In the embodiment illustrated b way of example in Fig. 4, the air regu ator replaces the suction valve. If by means of lever h, which may be actuated by hand at the handle i or by a velocity regulator at k, the wedge m which, in a known manner,

adjusts the stroke of the fuel pump Z and the slide a of the air control are adjusted for a given load of the engine, the flap b will be displaced at every stroke into a position correspondin to the existing number of revolutions, t at is, it will lay open a greater or smaller sectional area according to the number of revolutions. If, however, the load is to be varied at a constant number of revolutions, lever h is operated. On turning said lever in the direction of the arrow, the delivery of the fuel pump Z will be reduced, and, at the same time, the area adjusted by slide a will also be reduced, whereas the loadin of the area will be increased, so that, if t e flap b be roperly designed, the correct weight 0 air corresponding to the weight of the fuel will be su plied.

f using the air regulator instead of the air valve, the air regulator is disposed in the pipe intermediate the working cylinder f and pum g. It is not necessary that the fuel supp ied by the pump should be injected into the cylinder head, but the fuel nozzles together with the air regulator may be arranged in the pipe between the working cylinder and the charging pump.

. We claim 1. In an internal combustion engine in combination a fuel pump, an air inlet, means for adjustin said air inlet in accordance with the regu ation of said pump and an air-float at the rear of said air inlet.

2. In an internal combustion e "me in combination, a fuel pump, an air inlet, a slide adjustable by hand for throttling said air inlet in accordance with the regulation of said pump and an air-float at the rear of said air inlet.

3. In an internal combustion engine in combination, a fuel pump, an air inlet,

means for adjusting said air inlet in accordance with the regulation of said pump and a lloladed. flap va ve at the rear of said air 1n e 4. In an internal combustion engine in combination, a fuel pump, an air inlet, a slide adjustable by hand for throttlin said air inlet in accordance with the regu ation of said pump and a loaded flap valve at the rear of said air inlet.

5. In an internal combustion engine in combination, a fuel pump, an air inlet, means for ad'usting said air inlet in accordance with t e regulation of said pump and a sprin Loaded flap valve at the rear of said air e 6. In an internal combustion engine in wewee combination, a fuel pump, an air inlet, cordance with the regulation of said pump means for adjusting said air inlet in aeand a spring loaded flap valve at the rear of cordance with the regulation of said pump said air inlet, the spring load on said valve and a spring loaded flap valve at the rear being arranged to remain substantially con- 0 of said air inlet, the spring load on said valve stant during the operation of said valve and 15 being arranged to remain substantially conmeans for varying the spring load.

stant during the operation of said valve. In testimony whereof We aflix our signa 7. In an internal combustion engine in tures.

combination, a fuel pump, an air inlet, EDUARD SPPELER.

10 means for adjusting said air inlet in ac- PAUL SCTLER. 

